Shinsei Bank on Monday rebuffed a proposal from SBI Holdings Inc. to conditionally extend its unsolicited tender offer for the bank until November, saying again that it needs more time.

Shinsei said its proposed extension to Dec. 8 will give shareholders sufficient time to assess provided information so they can decide on whether to tender their shares. The bank is preparing to launch a defense against the hostile takeover bid launched in early September.

SBI, a major online financial group, is seeking to raise its stake in Shinsei from the current 20% to as high as 48%.